Home built 4x40 Recirc Pump

[Hillcrest Maples]

After scouring every recirc post on here going back 10 years I haven’t found anything on what people are using for recirc pumps on a 4x40. I just built a unit matching the CDL 125, but can’t seem to figure out a good pump for recirc. I also can’t understand how CDL gets away with only 1 needle valve on the concentrate side an no needle valve on the recirc line. Anyone done a setup like this before? Any insight would be much appreciated

[NaVGF]

I’m building now and I just plan to feed into the intake of the Procon high pressure pump. Close the valve for no recirculation and partial open to keep concentrate moving no extra pump needed. (I’m posting as a suggestion as well as looking for critique to my plan).

[Rselleck91]

So I run a procon pump and a stainless multistage Dayton pump. The procon feeds into a loop system with a t at the first vessel and another t at the last vessel. The multi stage pump and vessels just run a loop system. The t fitting give my a way to feed in and a way to bleed off with a needle valve. I run a 260 procon on 3 vessels. It’s perfect to batch up the sap to high sugar and then bleed off the concentrated sap.

A ro without a dedicated recir pump is like a old diesel truck before they ran turbochargers.

[WoodButcher]

exactly what he NaVGF said. you just need a dedicated line teeing off your post exit running to the recirc needle valve and then out of the valve into a tee just before your procon inlet. check out my build link below.

[Hillcrest Maples]

I looked at the Daytons but couldn’t find anything rated for potable water. Ended up with Flint and Whalling multistage booster rated for 300psi case pressure and will boost up to 189psi. All stainless and potable water rated. Figure between the procon and this I’ll have no problem getting a steady 225 psi through my MES Membrane and good recirculating flow. Probably overkill for 1 4” but I don’t pull enough sap out of my 200 silver maples to make sure I’d have enough permeate to wash both memebranes.

[Rselleck91]

exactly what he NaVGF said. you just need a dedicated line teeing off your post exit running to the recirc needle valve and then out of the valve into a tee just before your procon inlet. check out my build link below.

I don’t see anything here that will keep a membrane from fouling up.

[WoodButcher]

I don’t see anything here that will keep a membrane from fouling up.

Nothing prevents a membrane from fouling, but there are things that can help slow the process down. And recirculation is one of them. Not doing a higher pressure single pass = less fouling. It also allows you to make the membrane utilization more uniform.
Please look up any post with Bowhunter involved. super smart engineer who helped me on my build... there is a ton of info on this site about recirculating, full membrane utilization, etc. You just have to take the time and find it......

[NaVGF]

RSellek91 Do you have a diagram or a reference for your setup? Just trying to visualize and the hamster is off the wheel until at least June.

[neil2fish]

We built a 3 membrane 4x40 that does 300/hr from 2-8 at 275 to 300psi. Have a procon on a 2hp for pressure pump and a Gould multistage doing 600gph for recirc on a loop as described above. the most important thing i learned was that 15% permeate is what you should target so as not to load your membranes. 15% of total flow over your membranes is what should come out as permeate. Increase flow, not pressure, to maximize permeate removal. with what i described, we take 4.5 gpm/1.5gpm, +/-permeate/concentrate with no appreciable loss of flow or gain in pressure. 10 minute sap rinse at 50psi every hour just for good measure. Could not have done any of it without the help and guidance found here. Best of luck